The proposed studies are aimed at identifying and characterizing the Plasmodium falciparum merozoite surface glycoproteins which are believed to play a role in the invasion of the host erythrocyte and possible immunologic response of the host. Surface glycoproteins will be identified by proteolytic enzyme digestion of radiolabelled, purified, merozoites. Tryptic peptide analyses, using ion exchange column chromatography, two-dimensional tryptic peptide mapping procedures, will determine the number of discrete surface glycoproteins and their possible interrelationships. Preliminary analyses are proposed on determining the strategy of glycosylation of glycoproteins. The glycoproteins found on he surface of infected erythrocytes will be similarly analyzed and related to the merozoite glycoproteins in order to determine if they are similar to separate gene products. Pulse-labelling and tunicamycin (a glycosylation inhibitor) studies will be employed to determine if parasite specified glycopolypeptide precursor molecules can be identified in infected erythrocytes.